There are known various constructions of devices for loading and unloading ships and other cargo carriers. Exemplary of such devices is the reknown standard crane which adorns ports worldwide. These cranes are mounted on the quay of a port, or in some constructions to a mobile base. The crane generally is provided with a hook which suitably is configured so as to engage cargo to be loaded to, or unload from, a ship moored to the quay. To load, the crane hook engages cargo resting upon the quay and is then moved vertically and horizontally toward the moored ship. The cargo is then deposited at a desired location on the ship and precisely located through independent means. Unloading proceeds via a similar process.
This typical construction suffers from a variety of problems. First, inasmuch as the crane hook cannot handle cargo during its return time from the ship back to the quay during loading, efficiency of the process is low. Second, the utilization of independent means, especially during unloading as required on the quay to remove deposited cargo, mandates coordination between handlers which is often difficult to obtain. In the case where the removal of cargo from the quay fails to coincide with the unloading cycle of the crane, either a pile up or extensive "dead time" is experienced.
Others have attempted to obviate some or all of these problems. One early construction is the cargo handling apparatus of U.S. Pat. No. 1,525,950, to Prescott. The apparatus disclosed therein comprises a bridge, a cantilever arm, a ship leg and a pier leg. The leg members and arm utilize continuous conveyors for conveying the cargo remote from the apparatus. The conveyors comprise trays having concave-grid arm bottoms which move circuitously throughout the entire apparatus.
U.S. Pat. No. 3,952,891, to Terayama et al., and 4,172,685, to Nabeshima et al., provide methods of improved handling of cargo with use of container cranes.
U.S. Pat. No. 4,175,908, to Anderson, discloses an apparatus and method of loading and unloading heavy objects. The complex apparatus disclosed therein provides an alternative to harbor cranes or pontoon cranes. According to the method a heavy object is lifted from the quay, or a vehicle driveable along the quay, moved along girders to a position above the hold of a ship, and then lowered into the hold of the ship. While providing a viable method of loading heavy objects, the method suffers from inefficiency and other problems discussed hereinabove.
U.S. Pat. No. 4,293,077, to Makino, is directed to a container handling apparatus which provides an improvement of an existing crane. The apparatus comprises a traveling portal frame having a container transfer space and an elevating device. A truck is also provided as a container transport vehicle. In operation, the portal frame is moved along the quay to a desired position. While providing mobility, such action limits the usefulness of that portion of the quay which must be reserved for this frame movement.
It should be evident, while the art has provided ameliorations of harbor crane structures, a truly efficient method and apparatus for loading and unloading of ships has not heretofore been known. A further problem in the loading and unloading of ships is encountered when the cargo being handled may not be exposed to the elements. For example, unloading of paper goods in rainy weather may not be accomplished without destruction of at least some of the cargo.
In this regard, the aforesaid U.S. Pat. No. 1,525,950, discloses the use of a support means/shield means which is fitted over the hold of the ship. The cargo is not, however, protected from the elements as it is unloaded from the ship to the quay.
Russian Pat. No. 796,130 discloses the use of a flexible shield means which is fitted over the hatch of a ship and is interconnected to an encloses container handler. The shield means however is not capable of being adapted to different sized hatches or hatches at different angles due to the mooring of the ship.